Bit-stock



(No Model.)

O. D. WARPIELD.

BIT sToeK.

No. 267,732. Patented Nov. 21;, 1882.

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UNITED STATES PATENT OFFICE.

OLIVER D. WARFIELD, OF SPRINGFIELD, MASSACHUSETTS.

BIT-STOCK.

SPECIFICATION forming part of Letters Patent No. 267,732, dated November 21, 1882,

Application filed June 10, 1882. 4(No model.)

To all whom it may concern: i 4 Be it known that I, OLivEaD. WAEEIELD of Springfield, inthe county of Hampden and `State of hlassacliusetts,"have invented a new and useful Improvementin Bit-Braces, oi'which the following isadescription and specification.

rlhe object of my invention is to provide a bit-brace. into which aboring-bit may be easilyl and quickly adjusted, and by which it Will be securely and rmly held during the operation of boring; and I accomplish this by the mechanism substantially as hereinafter described, and illustrated in the accompanying drawings, in Which- FigureI is a side view` of a bit-brace made according to my invention. Fig. II isa longitudinal section ot' the same through the socket portion of the brace, showing the fastening mechanism of full size; and Fig. III is an end view ofthe socket end of the brace.

In the drawings. 1 represents the rod or main part of the brace, the end of which may be somewhat enlarged, and in which is made the socket, as 2, which is made to approximately tit the shank of'- any ordinary boringbit, and on one side of this socket are made two ears, as 3. between which is pivoted, at 4, a cam, as 5, and ahole is made through one side of the socket end of the brace, through which projects a spring-detent, as S, secured to the brace, as at 7, and lthe cam, as 5, is made to impnge against this springdetent and force it into thesocket when the cam isin the position shown in black lines; but when the cam is in the position shown in dotted lines its pressure against the detent is removed. A threaded hole is made through the side ofthe socket opposite the detent,as8, through which may be turned a thumb-screw, as 9, so that its inner end may project into the socket 2.

When itis desired to nsethis brace the shank ofthe boring-bit is inserted into the socket, as 2, with the thumbscrew 9 turned out, and the cam, as 5, in the position shown in dotted l lines, and the thumb-screw is then lturned in until its inner end strikes against the shank of the bit, and the cam 5 is then forced down into the position shown in black lines, which movement of the cam forces the detent 8 inward, with its inner end firmly pressed against the shank of the hit on the side opposite the tiiumbscrew 9, and the hit is thereby tirmly held in place in the socket of the brace. To loosen the bit it is only necessary to move the cam, as 5,into the position shown in dotted lines, and the bit is then easily removed irom the socket.

It is evident that instead of a flat spring, as 6, with one end attached to the deteiit and the other secured to the brace, as at 7, thedetent,

as 8, may be provided with a shonlderon its outer end, and its hole counterbored, with a spiral spring placed therein and pressing out- Ward against the shoulder on the outer end of the detent, to hold the latter always outward, except when forced inward by the cam, as shown in dotted lilies in Fig. II.

By using the adj usting-screw, as 9, the slight differences in the size ot' different shanks of bits may be easily compensated for, so that the same movement ot' thecnm and detent will always be sufcient to secure the bit in the brace-socket.

Having thus described my invention, what I claim as new is In an improved bit-brace, the combination, with the brace, provided with a socket to receive the shank ofthe bit, of a cam pivotedto the socket end, a springdetent between said cam and the socket, and adapted to be forced inward into the socket by the cam, and an adjusting-screw adapted to be turned into said socket on the side thereofl opposite said springdetent, substantially as described.

. OLIVER D. 'WARFIELD Witnesses:

T. A. CURTIS,

CEAS. H. Woon. 

